m68k: Check syscall_trace_enter() return code

[ Upstream commit 2ca8a1de4437f21562e57f9ac123914747a8e7a1 ]

Check return code of syscall_trace_enter(), and skip syscall
if -1. Return code will be left at what had been set by
ptrace or seccomp (in regs->d0).

No regression seen in testing with strace on ARAnyM.

Signed-off-by: Michael Schmitz <schmitzmic@gmail.com>
Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
Link: https://lore.kernel.org/r/20230112035529.13521-2-schmitzmic@gmail.com
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/arch/m68k/68000/entry.S b/arch/m68k/68000/entry.S
index 259b3661b614168ff8ab377587c66b1478222218..94abf3d8afc52588806f7e7007ddd6ee896b399a 100644 (file)
--- a/arch/m68k/68000/entry.S
+++ b/arch/m68k/68000/entry.S
@@ -47,6 +47,8 @@ do_trace:
        jbsr    syscall_trace_enter
        RESTORE_SWITCH_STACK
        addql   #4,%sp
+       addql   #1,%d0
+       jeq     ret_from_exception
        movel   %sp@(PT_OFF_ORIG_D0),%d1
        movel   #-ENOSYS,%d0
        cmpl    #NR_syscalls,%d1

diff --git a/arch/m68k/coldfire/entry.S b/arch/m68k/coldfire/entry.S
index 52d312d5b4d4f68337aa8f9b711f50b1a1ad9eda..fb3b06567745972cbceb9ae5ad9395432c7cea99 100644 (file)
--- a/arch/m68k/coldfire/entry.S
+++ b/arch/m68k/coldfire/entry.S
@@ -92,6 +92,8 @@ ENTRY(system_call)
        jbsr    syscall_trace_enter
        RESTORE_SWITCH_STACK
        addql   #4,%sp
+       addql   #1,%d0
+       jeq     ret_from_exception
        movel   %d3,%a0
        jbsr    %a0@
        movel   %d0,%sp@(PT_OFF_D0)             /* save the return value */

diff --git a/arch/m68k/kernel/entry.S b/arch/m68k/kernel/entry.S
index 97cd3ea5f10b837949b124024951912d6973e8f6..9a66657773beb3613087d8319742830646a4eae1 100644 (file)
--- a/arch/m68k/kernel/entry.S
+++ b/arch/m68k/kernel/entry.S
@@ -160,9 +160,12 @@ do_trace_entry:
        jbsr    syscall_trace
        RESTORE_SWITCH_STACK
        addql   #4,%sp
+       addql   #1,%d0                  | optimization for cmpil #-1,%d0
+       jeq     ret_from_syscall
        movel   %sp@(PT_OFF_ORIG_D0),%d0
        cmpl    #NR_syscalls,%d0
        jcs     syscall
+       jra     ret_from_syscall
 badsys:
        movel   #-ENOSYS,%sp@(PT_OFF_D0)
        jra     ret_from_syscall